Temperature regulator



Jime l l, 1929. F. c. REED'ER TEMPERATURE REGULATOR Filed Jan. 2, 1925v(atroz uni l nvwnfot m, m, W w

Patented June ll, 1929.

UNITED STATES f 1,711,261 PATENT OFFICE.

FRANK C. REEDER, 0F KNOXVILLE, TENNESSEE, ASSIGN OR, BY MESNEASSIGNMENTS,

TO THE FULTON SYLPHON COMPANY, OF KNOXVILLE, TENNESSEE, A CORPORA- TIONOF DELAWARE.

TEMPERATURE REGULATOR.

Application led January 2, 1925.

This invention relates to temperature regulators, and more particularlyto apparatus for regulating the temperature of electrical transformersof the type employing liquid conveying cooling coils immersed in aninsulating fluid which surrounds the transformer windings.

' Transformers cooled entirely by the flow of a liquid, such as water,require a considerable supply of water when running full load and whenrunning at a very slight load the water circulation should becorrespondingly decreased. If too great an amount of water is suppliedthe transformer will lbe overcooled and moisture from the atmospherewill condense inside the transformer, thus reducing the dielectricstrength of the insulating fluid, usually oil, surrounding thetransformer windings. Moreover, the cost of the cooling liquid is aconsiderable item in the operation of transformers and should be reducedto a minimum by providing only the amount actually required for propercooling.

It has heretofore been proposed to provide temperature regulators fortransformers of the cooling coil type lby employing a regulatorcomprising a thermostatic element and a controller element forregulating the flow of the cooling medium. This thermostatic elementincludes a tubular receptacle containing heavy oil and a corrugatedmetal tube. The controller element includes a tubular member having itsupper en'd connected by a tube of 'small diameter to the upper end ofsaid tubular receptacle. A corrugated metal tube, capable of beingcompressed when an increase of temperature causes the heavy oil in saidreceptacle to expand, is positioned in the tubular member. When thetemperature of said oil increases, the pressure thus developed istransmitted to the tubular member to effect compression of thecorrugated tube therein. As a result, a piston is actuated to open avalve controlling the supply of cooling liquid for the cooling coils,said valve being positioned on the inlet side of the coils. The tubularreceptacle of the thermostatic element is embraced by a heating coilconnected in circuit with t-he secondary winding of a small transformer,the primary windings of the latter being connected'with the secondary ofthe main transformer to be cooled.

This proposed arrangement has proven unv Serial No. 248.

the same as that of the transformer windings, and the emissivity of theoil must likewise correspond to that of the transformer windings.Moreover, the auxiliary transformer and the connections therefor to themain transformer, together with the above heat requirements, renders itpractically impossible to install the device in transformers other thanthose particularly designed and built with that object in view.

Another serious defect in the above type of regulators results from theplacing of the control valve on the inlet side of the cooling coils.When so positioned the coils will not remain lillc'd with water afterthe valve is closed. Consequently, when the valve is opened the coilsare immediately filled with cold water which over-cools the transformer.

A11 object of the present invention is to overcome the abovedifficulties by providing a temperature regulator which is actuatedsolely by the change in temperature of the insulating fluid, no heatingcoil or electrical connections to the transformer windings beingrequired.

Another object of the invention is to provide a novel temperatureregulator comprising a temperature control valve which is positioned onthe discharge side of the cooling coils for preventing undesirablefluctuations in the temperature.

A further object of the invention is to provide a novel temperatureregulator of rugged construction which may be readily and inexpensivelyinstalled in transformers now in use. VOther objects will appear as thedescription proceeds.

The invention is capable of receiving a variety of mechanicalexpressions, one of which is illust-rated in the accompanying drawingsbut it is to be expressly understood that the drawings are for purposesof illustration only and are not designed as a definition of the limitsof the invention, reference being had to the appended claim for thispurpose.

In the drawings:

Fig. 1 is a somewhat diagrammatic side elevation illustrating oneembodiment of the present invention;

Fig. 2 is an enlarged detail sectional view of one form of athermo-sensitive bulb that may be employed; and

Fig. 3 is a section taken on the line 3 3 of Fig. 2.

Referring to the drawings wherein like ref- I bodyl of insulatingliquidV of any suitable character, such as oil, is contained in casing5,- the level 7 of the oil being such as to completely. immerse. thetransformer windings 1 4. Preferably, a pair of concentric, parallelcooling coils 8 are mounted within the casing adf jacent the innerperiphery thereof, and in a position to surround the. transformerwindings 4. Discharging into the coils 8 Vand connected thereto in anysuitable manner are a y-pair of pipesr9 which are preferably disposedexteriorly of the casing and which are provided with hand valves 10. AY-coupling 11 is preferably employed for connecting the.V

pipes 9 to a cooling` water supply pipe 12. Connected to the dischargeend of the coils 8 area pair of ypipes 13- which may be connected bymeans of a T-coupling 14 to a cominonclischarge 15.V In the form shown,a T- `couplinglG is employed for dividing pipe 15 into two parallelbranches 17 and 18 connected with a'common waste pipe`19. PreferablyV amanually operable valve 2O of any suitable type is provided in' branch18.

Y Suitable. means are provided for automatically controlling orregulating the flow of thecooling liquid through the branch pipe 17, andsaid means are controlled by the temperature of the insulating liquidcontained in casing 5.

. As shown, the regulating means are of the type illustrated anddescribed in the patent to f Fulton, No, 1,328,277, dated January 20,1920,

" and comprise a valve structure 21 operatively connected to the'branchpipe 17 together with f athermo-sensitive unit' 22 that is immersed inthe insulating liquid closely adjacent the transformer windingsl.

The valve structure 21 includes a frame 23 in which" is mounted anexpansible and col- .nected to a. valve stem 24 for actuating aVsuitable valve positioned in valve Vcasing25 lapsible corrugated vesseloperatively coninterposed in thev branchpipe 17.y Suitable regulatingmeans of any known typeare provided for controlling the expansion `ofsaid vessel. 4 Y i Y The thermo-sensitive unit comprises a tube 26 whichpreferably threaded at. its upper end 26a into the cover plate 6 Aand isprovided with a plurality of openings 261 in the lower portion of itsside walls. A removable' cap 26c may be threaded onto the lowerend ofVthe tube. VPositioned in the lower portion ing` liquid, and preferablyin engagement with cap 26is a bulb 27 which is partially nlled with alvolatile liquid of any suitable character,as chloroform for example. A

sel and forcing valve stem24 downwardly Vtube 28 of small diameterconnects the' interior of the bulb 27 with the interior of thecorrugated vessel of the valve structure 2l. A drain 29 may be providedfor the casing' 5.

In operation, pressure is maintained at all times on supply pipe 12andthe 4cooling coils 8 are always filled with the cooling liquid. Asthe load on the transformer increases, the resulting heatV raises'thetemperature of the insulating oil, and the latter -in turn volatilizesthe liquid in bulb27. The pressure thus generated in the bulb istransmitted through pipe 28 to the corrugated vesseland the valvestructure 21,V expanding said vestoopen kthe valve in valve casing 25and permit the cooling liquid to circulate-in coils 8. The adjustingmeans of the valve structure is such that the valve will be opened asuitable amount to control the flow of cooling liquid and maintain thetransformer windings at the Adesired temperature. The openings 26b intube 26 permit free circulation ofthe insulating liquid around the bulb27. Since the control valve is placed on the discharge side of thecooling'coils the'latter vwill always be filled with water and suddenchanges in temperature will'be avoided, thus materially increasingthe'eiiiciency of the transformer. lf desired, valve20 may be opened apredetermined amountto provide a continuous'circulation of coolinglwater. ln-this instancethe temperature regulation will be only partiallyautomatic.

Valve 2O may also beemployed lfor* draining the cooling coils 8, the:valves 10 being closed.

lOO f There is thus provided a regulator which Y is automatic-VinVoperation and which at all times supplies only the amount of waterrequired'. for maintaining the transformer windings at the desiredtemperature, thereby controlling the amount of water used and reducingthe cost ofthe same to a minimum. The device may be readily installed intrans-Y formers now in use without the necessity of altering electricalconnections.L The amount of cooling liquid supplied variesdirectly withVthe temperature of the insulating liquid.

Y Nh'ilezonly one' embodiment of the inven-V tive idea has beenillustrated in the accompanying drawings, it is to .be understood thatthe inventionis not limited thereto since the invention is capable ofbeing carried out in a. variety of ways, some of which willnow readilysuggest themselves to those skilled in the art,while changes may be madein details of construction and arrangement Vwithout departing from thespirit of .the invention.

Reference is therefore to be had tothe claim of tube 26, below the level7 of the insulat i definition lof the limcasing thereforccntaining aninsulating liquid, a cooling coil in said casing and liqinserted Withinsaid tube7 an expansible and uid and having inlet and outletconnections, Collapsible vessel operatively connected to 10 a valve inthe outlet connection of said Coil said valve, und a pipe connectingseid bulb whereby the flow of cooling medium may and vessel.

be stopped while maintaining said Coil 'full In testimony whereof I havesigned this of said medium, :L perforated tube dependspeeiiieation.

ing in said insulating liquid from the top of the casing, :1 bulbcontaining a volatile fluid FRANK C. REEDER.

